Container Cleaning Machine in recent years have grown in size to handle the volume of returnable containers that has come about due to attention given to wasteful practices of the past. In addition to increase in sizes of machines attention has been directed to the conservation of nonreplenishable fossil fuels and the rising cost of such fuels. Heat is required in these machines to remove labels and to attack and remove dirt and foreign objects in the containers. The consumption of heat in the usual cleaning or washing machines can be attributed to heating the carriers and conveyors, heating the containers, heat radiating losses, and heat losses to sewer discharges. Radiation loss may be reduced by use of insulation, but the size of the machines and the need for externally attached accessories makes insulation application a distinct problem. The heating of the conveyor and carriers is useful but calls for heat supply over and above that required to heat the caustic solution to its effective temperature level.
The conservation of fuels and the need for heat in cleaning machines presents problems which current generations of machines have not overcome. Some of the prior container cleaning machines have provided undershot jet sprays for containers entering the cleaning machine, in which the spray liquid is supplied from a compartment near the discharge end of the cleaning machine. However, the undershot spray arrangement does not effectively conserve the energy needed for producing the heated liquid supplied to the undershot spray.